[en] The patients being dialysed by means of artificial kidney should be controlled towards concentration of calcium in their bodies. The method being actually used bases on neutron activation analysis. The patients are irradiated by small dose of thermalized neutrons. During the nuclear reaction ⁴⁸Ca(n,γ)⁴⁹Ca the gamma radioactive ⁴⁹Ca is being produced. The analysis of its gamma spectra gives the calcium concentration. The history of all discoveries and results of basic research which created a scientific background for elaboration of described method, being commercially used now in medical practice, have been also presented. 10 figs, 1 tab

[en] Combinatorial chemotherapy, which has emerged as a promising treatment modality for intractable cancers, is challenged by a lack of tumor-targeting, robust and ratiometric dual drug release systems. Here, docetaxel-loaded cRGD peptide-decorated redox-activable micellar mertansine prodrug (DTX-cRGD-MMP) was developed for targeted and synergistic treatment of B16F10 melanoma-bearing C57BL/6 mice. DTX-cRGD-MMP exhibited a small size of ca. 49 nm, high DTX and DM1 loading, low drug leakage under physiological conditions, with rapid release of both DTX and DM1 under a cytoplasmic reductive environment. Notably, MTT and flow cytometry assays showed that DTX-cRGD-MMP brought about a synergistic antitumor effect to B16F10 cancer cells, with a combination index of 0.37 and an IC₅₀ over 3- and 13-fold lower than cRGD-MMP (w/o DTX) and DTX-cRGD-Ms (w/o DM1) controls, respectively. In vivo studies revealed that DTX-cRGD-MMP had a long circulation time and a markedly improved accumulation in the B16F10 tumor compared with the non-targeting DTX-MMP control (9.15 versus 3.13% ID/g at 12 h post-injection). Interestingly, mice treated with DTX-cRGD-MMP showed almost complete growth inhibition of B16F10 melanoma, with tumor inhibition efficacy following an order of DTX-cRGD-MMP > DTX-MMP (w/o cRGD) > cRGD-MMP (w/o DTX) > DTX-cRGD-Ms (w/o DM1) > free DTX. Consequently, DTX-cRGD-MMP significantly improved the survival rates of B16F10 melanoma-bearing mice. Importantly, DTX-cRGD-MMP caused little adverse effects as revealed by mice body weights and histological analyses. The combination of two mitotic inhibitors, DTX and DM1, appears to be an interesting approach for effective cancer therapy. (paper)

[en] The decay of ⁴⁹ K has been studied using a mass-separated ion beam by neutron and gamma-ray singles and multiparameter spectroscopic measurements. The ⁴⁹ K activity was producted by 600 MeV proton fragmentation reactions in a uranium target. The observed beta-strength function display two resonances centered at about 6.5 MeV and 9.5 MeW in ⁴⁹Ca. This structure is discussed in simple shell-model terms. (orig.)

No abstract available

[en] The distribution of bone calcium between morphologically identifiable cortical and trabecular bone obtained by dissection and quantitated by neutron activation analysis (NAA) is described. The skeleton of a female beagle dog was dissected into approximately 400 pieces and assayed for ⁴⁹Ca produced in the University of California, Irvine TRIGA reactor. For each of the skeletal sections, we give the initial weight of the alcohol-fixed tissue, which includes cortical bone, trabecular bone, marrow, and cartilage, and a final tissue weight after the marrow and trabecular bone have been dissected away; total section and cortical section calcium weights are reported. The level of detail is represented, for example, by the vertebrae, which were divided into three parts (body, spine, and transverse processes) and by the long bones, which were divided into 10-12 parts such that characterization of the epiphysis, metaphysis, and diaphysis was accomplished. The median percentage cortical calcium values for cervical, thoracic, and lumbar vertebrae were 82%, 56%, and 66%, respectively; however, variation within these groups and among individual vertebral sections was about a factor of 2. For long bones, the median percentage cortical calcium varied from 90-100% in the midshaft to below 50% in the proximal and distal sections. The final calculated cortical tissue-to-calcium mass ratio (TCR) varied from about 4.5 for midshafts of the long bones to about 9 for thoracic vertebral bodies and indicated that the mineral fraction of cortical bone is not constant throughout the skeleton. The ratio of cortical to trabecular calcium in the skeleton was 79.6:20.4

[en] The level statistics of the spherical mean-field plus pairing model is investigated based on the exact solutions obtained from the extended Heine-Stieltjes correspondence. It is shown that the level statistics for ⁴⁹Ca and ⁵⁰Ca calculated from the model with single-particle energies and a pairing strength extracted from experimental data indeed exhibits a chaotic behavior within the phase transitional region, while most isotopes display regular spectra. (authors)

No abstract available

[en] Measurements of exhaled Ar-37 produced by total-body neutron irradiation of Ca-40, were used to determine total-body calcium in ten human subjects. There was a good correlation between the Ar-37 yield and total-body calcium determined by measurement of Ca-49

[en] The neutron capture cross section of ⁴⁸Ca was measured relative to the known gold cross section at kT=52 keV using the fast cyclic activation technique. The experiment was performed at the Van de Graaff accelerator, Universitaet Tuebingen. The new experimental result is in good agreement with a calculation using the direct capture model. The 1/v behavior of the capture cross section at thermonuclear energies is confirmed, and the adopted reaction rate which is based on several previous experimental investigations remains unchanged. copyright 1997 The American Physical Society

No abstract available